Determination in relation to safety of operation of the minimal load on the front steering axle of a tractor with implements attached

The investigations revealed several correlations. An example is the relation between the required 20% load on the front axle of tractors and the generally used coefficient of the dynamic longitudinal stability of tractors, i.e. 2·5–3. Results of tests aimed towards the safety of tractor manoeuvrability indicate, that the coefficient may be lower. Tests carried out in 1970 with tractors of higher hp have confirmed that the directional stability tends to decrease significantly with higher speeds of travel, while it improves with a higher total weight of tractor with implements attached. Tests showed that: (1) Speed of travel of a tractor with mounted implements should be limited to 15 km/h at the maximum. (2) Hitching systems for 2-wheel trailers should have the link point positioned directly in the axis of the rear p.t.o. of the tractor. (3) Trailers should be linked to the lower hitch of the tractor, as revealed from test results. From the test results a coefficient was determined of the dynamic load on the front steerable axle of the tractor—relation of the static load to actual load during travel of a tractor. This coefficient is in the range 1·96–1·54. Its value depends on the speed of travel and gradient. An average value 1·82 was applied in calculations.